I wouldn’t go as far as saying that… There’s going to be alot more to it than just hacking and welding with the plasma and tig. You don’t get this dialed in perfectly straight and parallel and your car won’t track straight to save your life.
Are you going to run the entire rear subframe from the audi with the LCA’s and strut housings/uprights, or are you planning a different subframe/suspension in back?